Field
The present disclosure relates to an extension device for a bone anchor, which includes at least one tab. The tab includes an elongate shaft portion that forms part of a channel for providing a stabilization rod to a recess of a receiving part of a bone anchor, and also includes a coupling portion, which is configured to be attached to the receiving part.
Description of the Related Art
Document US 2006/0247658 A1 discloses an apparatus for guiding a surgical implant to a bone anchor during surgery. The apparatus includes a bone anchor extender releasably attachable to the bone anchor, where the bone anchor extender clips onto a head of the bone anchor to assist in guiding the surgical implant to the bone anchor. The bone anchor extender includes a clip with a pair of raised tabs on opposite side portions of the clip. A medial portion and the corresponding side portions of the clip have a thickness allowing the side portions to elastically deform and/or bend in a lateral direction and then revert back to their original shape. The raised tabs have angled faces and retention edges which assist in guiding the extender onto the head and snap the clip to the bone anchor.
Document US 2005/0085813 A1 discloses a brace-screw assembly. The assembly is delivered along with an anchor extension device, or cannula, for anchoring in a vertebrae pedicle. The extension device has flexible fingers at the distal end and protrusions in the form of small pyramids are formed on the inside of these fingers. These pyramids fit into a tight mating relationship with mating structures of the screw assembly. To attach or release the extension device to the assembly, the fingers are caused to fly outward when the pyramids and mating structures leave their mated states.